P450 (cytochrome) oxidoreductase, or, POR, is a human gene. Other names include: NADPH--cytochrome P450 reductase; P450R; CPR; NADPH-cytochrome P450 reductase; CYPOR. The encoded protein is an enzyme with an amino acid length of 677 and a mass of 76.7 kDa. Other isoforms may exist. P450 (cytochrome) oxidoreductase is a member of the Flavoprotein pyridine nucleotide cytochrome reductase family. This gene shares homology with other species, including: Mouse, Rat.